Effect of the Fusion Fuels' Polarization on Neutron Wall Loading Distribution in CFETR

The China Fusion Engineering Test Reactor (CFETR) is a new superconducting tokamak device being designed in China, aiming to bridge the gaps between ITER and future fusion power plants. In addition to the temperature dependence, the cross section also depends on the spin states of the reactant nuclei. In this paper, we calculate the neutron source and neutron wall loading (NWL) distributions and investigate the effect of spin polarization on them. For the two unpolarized scenarios at the CFETR, the neutron source distributions have obvious differences, but the poloidal distributions of the NWL have a similar tendency and are just a little different except near the outboard midplane. For the hybrid mode scenario, the maximum of the NWL is near the outboard midplane. However, for the full parallel or antiparallel polarization, the NWL distributions have a big difference in the poloidal direction, and the maximum of the NWL occurs in the upper region of the first wall. The calculation results show that it is possible to optimize blanket design by using polarized fuels at the CFETR, and then increase the working life of the first wall.